van Berkel 2014

Methods	Random allocation Unblinded Study duration: 12 months Drop out: 11% Location: Amsterdam, the Netherlands
Participants	Population: all employees from 2 Dutch research institutes were invited to participate, between April‐November 2010 Intervention group: 129 participants Control group: 128 participants Demographics: mean age of the study population was 46 years. 67% of participants were women. About 60% of the study population had a healthy weight (BMI 18.5‐25).
Interventions	Duration of intervention: 6 months but the participants were followed up for 12 months. Intervention: the Mindful VIP intervention consists of 8 weeks of in‐company mindfulness training with homework exercises, followed by 8 sessions of e–coaching. The homework exercises comprised a variety of formal (“body scan” meditation, sitting meditation) and informal exercises (small exercises, such as breathing exercises when starting up the computer, and grocery shopping mindfully). Additionally, free fruit and snack vegetables were provided during the 6 months. In addition, lunch walking routes, and a buddy‐system were offered as supportive tools. Control: received information on existing lifestyle behaviour‐related facilities that were already available at the worksite.
Outcomes	Outcome name, measurement time/tool (units of measurement) Vigorous physical activity in leisure time (minutes/week) assessed with questionnaire and accelerometer‐inclinometer Sitting at work (minutes/week) assessed with questionnaires Fruit intake (servings/day) Determinants of lifestyle behaviours
Notes	The authors report no conflicts of interest.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were individually randomised to either the intervention or control group, using a computer‐generated randomisation sequence.
Allocation concealment (selection bias)	High risk	After randomisation, the research assistant notified each participant by e‐mail about the group to which he or she was allocated.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of the participants and the trainers was not possible.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Sitting time at work was assessed by questionnaires. Participants receiving the intervention would have been aware of the goals set and the purpose of the intervention and may have misreported outcomes.
Incomplete outcome data (attrition bias) All outcomes	Low risk	8 participants were lost to follow‐up from the intervention group and 17 from the control group. The loss to follow‐up in the control group was twice that in the intervention group. The authors conducted intention‐to‐treat analysis by linear mixed‐effect models.
Selective reporting (reporting bias)	Low risk	All outcomes mentioned in the study protocol were reported.
Baseline comparability/ imbalance	Low risk	Mean age was similar between the intervention group and control group. There were 63.6% women in the intervention group and 71% in the control group. All participants were from two Dutch research institutes.
Validity of outcome measure	High risk	Validity of the questionnaire used in the study has not been tested.